Using Flashback Database on 11g

Question

hi everyone,
My 11g db is size 50 GB on a very strong Windows server.
No performance problems whatsoever.
If I enable Flashback Database logging am I likely to notice any performance degradation? The data is not really heaviily changed.
What about disk space - does it use the existing redo/archive logs or does it create different logs for the flashback feature?
Thanks for your opinions.
John

Answer 1

user629010 wrote:
hi everyone,
My 11g db is size 50 GB on a very strong Windows server.
No performance problems whatsoever.
If I enable Flashback Database logging am I likely to notice any performance degradation? The data is not really heaviily changed.Even if the data is not heavily changed, with the internal changes happening, there would be some activity always generating Redo/Undo. You would want to check the working of the RVWR process to see any possible waits over it. In addition to this, if the speed of the writing of RVWR is not good enough to write, you would see the contention on the Undo tablespace as it won't be freed as long as the corresponding writes are not saved by RVWR.
>
What about disk space - does it use the existing redo/archive logs or does it create different logs for the flashback feature?Flashback database uses *.flb* files which , if I remember correctly ,grow in 8mb of chunks. FLasback database does not uses the existing redo logs. Yes, it does uses the archived logs in addition to the FLB logs. So before you think to use this featuture, you do want to check the retention period of the logs , also the disk space required to manage that much retention period.
HTH
Aman....
Thanks for your opinions.
John